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Barkhausen noise in a relaxor ferroelectric
Eugene V Colla1, Lambert K Chao, M B Weissman
1Department of Physics, University of Illinois at Urbana-Champaign, 1110 West Green Street, Urbana, IL 61801-3080, USA.
Physical Review Letters
|January 22, 2002
Summary
Barkhausen noise in lead magnesium niobate (Pb2/3Mg1/3Nb2/3O3) relaxors reveals shrinking dipole moments near the relaxor regime. This contradicts simple models of ferroelectric behavior.
Area of Science:
- Condensed matter physics
- Materials science
- Ferroelectricity
Background:
- Relaxor ferroelectrics exhibit unique dielectric properties.
- Barkhausen noise is a phenomenon related to domain wall motion in magnetic and ferroelectric materials.
- Lead magnesium niobate (PbMg(1/3)Nb(2/3)O3) is a well-studied relaxor ferroelectric.
Purpose of the Study:
- To investigate the nature of Barkhausen noise in PbMg(1/3)Nb(2/3)O3 within and near the relaxor regime.
- To analyze the temperature dependence of Barkhausen noise components.
- To understand the behavior of dipole moments during the transition to the relaxor state.
Main Methods:
- Applying a periodic electric field to PbMg(1/3)Nb(2/3)O3 samples.
- Measuring and analyzing Barkhausen noise, including its periodic and aperiodic components.
- Studying the temperature dependence of noise amplitude and spectral form.
Main Results:
- Barkhausen noise was observed in and near the relaxor regime of PbMg(1/3)Nb(2/3)O3.
- Temperature dependence analysis revealed a shrinking size of coherent dipole moment changes upon entering the relaxor regime.
- Observed behavior deviates from predictions of some existing theoretical models.
Conclusions:
- The study provides insights into the dynamics of relaxor ferroelectrics through Barkhausen noise analysis.
- The shrinking dipole moment size contradicts simple models, suggesting complex dynamics in the relaxor state.
- Further theoretical development is needed to explain the observed phenomena in PbMg(1/3)Nb(2/3)O3.